“内容”和“文本”有什么区别

I am using the terrific Python Requests library. I notice that the fine documentation has many examples of how to do something without explaining the why. For instance, both r.text and r.content are shown as examples of how to get the server response. But where is it explained what these properties do? For instance, when would I choose one over the other? I see thar r.text returns a unicode object sometimes, and I suppose that there would be a difference for a non-text response. But where is all this documented? Note that the linked document does state:

You can also access the response body as bytes, for non-text requests:

But then it goes on to show an example of a text response! I can only suppose that the quote above means to say non-text responses instead of non-text requests, as a non-text request does not make sense in HTTP.

In short, where is the proper documentation of the library, as opposed to the (excellent) tutorial on the Python Requests site?

The requests.Response class documentation has more details:

r.text is the content of the response in Unicode, and r.content is the content of the response in bytes.

It seems clear from the documentation is that r.content

You can also access the response body as bytes, for non-text requests:

 >>> r.content

If you read further down the page it addresses for example an image file